When it comes to expressing the idea of "multiple", there are many synonyms that can be used, depending on the context. Some of the most commonly used synonyms for "multiple" are "numerous", "several", "many", "countless", and "various". Other options include "diverse", "multifarious", "plethora", "abundant", "copious", "innumerable", "myriad", and "profuse". Each of these synonyms provides a slightly different nuance of meaning, and it often depends on the specific sentence and situation which is the most appropriate choice. However, regardless of the specific synonym chosen, they all convey the idea of there being more than one of something.